The configuration of the functional units, for example, with a base band unit, a fading unit, a noise unit, an I/Q-modulator and a high-frequency unit is variable within certain limits, and the function of functional units can be selected by the user from a predetermined range of functions.
The functions of measuring devices of this kind have conventionally been selected via operating keys (soft keys and hard keys). However, with this method of operation, the sequence in the signal flow according to which the individual functional units are connected to one another and influence the signal to be generated is not clearly evident. The currently active output sockets and the signals connected to them cannot be identified.
Regarding the technical background, reference must be made to U.S. Pat. No. 5,953,009. This document describes the allocation of trigger functions to the measurement channel of a digital oscilloscope by clicking on and moving icons symbolizing the trigger functions on the user interface. However, the signal flow of individual functional units and the function of these individual functional units cannot be identified from the user interface and cannot be selected on user interface.